Question 726135


The length of a certain rectangle is {{{L}}} {{{15cm}}} more than {{{three}}}{{{ times}}} its width {{{W}}}.

{{{ L=3W+15cm}}}.....eq.1

If the perimeter {{{P}}} of the rectangle is {{{94cm}}},
 
 {{{P=94cm}}}

what is the area {{{A}}}

we know that {{{P=2L+2W}}}, ...substitute {{{L}}} from eq. 1 and use given value for {{{P}}}

{{{94cm=2(3W+15cm)+2W}}}...solve for {{{W}}}


{{{94cm=6W+30cm+2W}}}


{{{94cm=8W+30cm}}}

{{{94cm-30cm=8W}}}

{{{64cm=8W}}}

{{{64cm/8=W}}}

{{{highlight(8cm=W)}}}

now find {{{L}}}

{{{ L=3W+15cm}}}.....eq.1

{{{ L=3*8cm+15cm}}}

{{{ L=24cm+15cm}}}

{{{ highlight(L=39cm)}}}

now we can find  the area {{{A}}}

{{{A=L*W}}}

{{{A=39cm*8cm}}}

{{{highlight(A=312cm^2)}}}